Field of the Invention
The invention relates to a wavelength conversion structure and a projection device.
Description of Related Art
Projector is a display device used for producing large-size images, and an imaging principle thereof is to convert an illumination light beam provided by a light source into an image light beam by using a light valve, and then project the image light beam onto a screen to form an image through a lens. Projector plays a very important role in information transmission, so that it is widely applied in many fields. A user uses a projector in collaboration with a projection screen to present figures or images according to content of image information provided by an image source.
Generally speaking, the projector uses a laser light beam emitted by a laser diode to excite phosphor in a phosphor wheel, and the phosphor is excited to provide an excitation light beam of different colors. Conventionally, a colloid having a white porous ceramic material is coated on the phosphor wheel, and then a fluorescent colloid is coated on the white porous ceramic material. However, such phosphor wheel has following problems. The amount of the colloid having the white porous ceramic material determines reliability and light-emitting efficiency of the phosphor wheel. If a proportion of the white porous ceramic material in the colloid having the white porous ceramic material is lower (a proportion of the colloid is higher), a scattering or reflecting effect thereof is poor; comparatively, if the proportion of the white porous ceramic material in the colloid having the white porous ceramic material is higher (a proportion of the colloid is lower), adhesiveness of the colloid having the white porous ceramic material adhered to the phosphor wheel is poor. Moreover, since the colloid having the white porous ceramic material is exposed in environmental media such as air, etc., when the phosphor wheel is rotated, the white porous ceramic material is liable to fall on a lens of the projector, which not only influences the light-emitting efficiency and reliability of the phosphor wheel itself, but also decreases light-emitting efficiency and reliability of the projector and quality of the image projected by the projector.
Moreover, since a large amount of heat energy is produced when the high-energy laser light beam continuously irradiates the phosphor wheel, the phosphor in the phosphor wheel has a thermal quenching phenomenon, i.e. a phenomenon that the light-conversion capability of the phosphor wheel is greatly decreased along with increase of temperature. Therefore, to resolve the aforementioned problem becomes an important issue studied and researched by related technicians of the field.
The info nation disclosed in this Background section is only for enhancement of understanding of the background of the described technology and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Further, the information disclosed in the Background section does not mean that one or more problems to be resolved by one or more embodiments of the invention was acknowledged by a person of ordinary skill in the art.